How to save tomato seeds

While saving tomato seeds is easy, starting with the right kind of tomato is very important. Most ordinary tomatoes you buy from the supermarket are not suitable for seed saving, because they are F1 hybrids. If you save seeds from an F1 hybrid the plants you grow will be different from the original plant, and so are not interesting for most people. Instead you should look for an heirloom or open pollinated variety to save seeds from, which will produce an identical plant to the original.

One of the best places to get tomato varieties suitable for seed saving is from another gardener who grows tomatoes and saves their own seeds. These people can often be found on Internet trading forums, like the Bloggers Seed Network.

Alternatively you can purchase seeds from a seed company that specialises in this type of plant, for example the Real Seed Catalogue. Be sure to look for a public statement that clearly says this is the type of plant they sell, similar to what's on the front page of the Real Seed Catalogue website, or you may end up with the wrong kind of seed.

While you can simply scoop out the seeds and spread them on a piece of paper to dry, fermenting them is easy and means you end up with cleaner seeds that are handier to store and trade with others. Always be sure to use tomatoes that have ripened as much as possible on the plant.

To start with, set the tomato upright and slice it in half horizontally through the middle.

Then scoop the seeds out into a small glass or ceramic container. In this case I'm using an old food jar. If you think it's necessary to keep the seeds covered and wet, you can also add a tablespoon or two of water.

Cover the container with plastic wrap, then poke a few holes in it for air with a knife or fork. Let it sit about five days in a warm place, out of direct sunlight, at which point you will probably see it has developed a layer of mould.

Mould on tomato seeds

This mould can range from a thin, almost invisible layer, to a thick green one. It may have a terrible smell, but this is normal, and nothing to be concerned about. Remove the plastic wrap and using a spoon remove as much of the mould layer as possible and discard it.

Rinsing tomato seeds

Place the container under gently running water. You will see the seeds tend to sink to the bottom, and you can let the water run off the top, or gently pour it off if necessary, until the seeds have been thoroughly rinsed. You may need to use your fingers to loosen a few stuck pieces. Then pour off as much water as possible.

Wet tomato seeds

Set the seeds on a coffee filter with the remaining water to dry. Don't use kitchen roll or the seeds will stick.

Dry tomato seeds

Be sure to always protect the seeds from direct sunlight. Once completely dry, scrape or rub the seeds off the coffee filter, with the help of a finger nail if necessary. Store in paper or plastic envelopes.